The present invention relates to a self-opener closure for composite packagings as well as to container spouts or bottle spouts of all types to be closed with film material. At the same time one specifically envisages liquid packagings in the form of such composite packagings of film-coated paper in which, for example, milk, fruit juices, all types of non-alcoholic beverages or generally liquids also in the non-food range are packaged. The closure may however also be applied to composite packagings in which goods capable of being poured such as sugar, semolina or all types of chemicals and likewise are kept or packaged. With this film-coated paper it is the case of a laminate material such as a paper or cardboard web coated with plastic such as, for example, polyethylene and/or aluminium. Usually the volumes of such packagings range from 20 cl up to 2 liters and more. Alternatively the self-opener closure may also be assembled on containers which are closed by film material, such as on all types of bottles made of glass or plastic or on similar containers. Such closures of plastic are known in various embodiments. If they are envisaged for a composite packaging, they essentially form a pour-out or discharge spout having a rim which radially projects from its lower edge and which forms a closing flange at this discharge spout. The spout is equipped with an outer thread onto which a rotary cap may be screwed as a closure. Such a self-opener closure is flanged onto the composite packaging in that it is sealingly welded onto the composite packaging with the lower side of its projecting edge, thus with the lower side of its flange. However, the free passage at the lower end of the spout is thereafter closed by paper and sealing film of the composite packaging. In the case of a bottle closure the pour-out spout for its part may be placed or screwed onto the opening of the bottle, and on its inner side is closed with a film membrane. The spout is equipped with an outer thread onto which the rotary cap may be screwed as a closure. To open, the film-reinforced paper passing through and below the welded-on spout, or the film membrane extending within the spout must be cut open or torn open towards the opening or pressed away so that the passage may be cleared and the fluid or the pourable material may be poured or shaken out of the container through the spout. For this a sleeve or a nipple is arranged within the spout which, on rotating the screwed-on cap, is caught by this and thus is rotated by this in the same direction of rotation. By means of a thread counter-rotating to the thread on the outer side of the spout and on the outer side of the sleeve, this sleeve moves continuously in a downward direction on screwing off the rotary cap, that is to say when said sleeve is displaced upwards with respect to the liquid packaging. The lower rim of the sleeve is provided with one or more tearing or cutting teeth. In this way, and as a result of its rotation and constant downwards movement, the sleeve is to press or cut a disk out of the film-reinforced paper or film membrane which runs beneath it.
However, such conventional self-opener closures do not function satisfactorily. The disks are not cut cleanly from the paper film or the film membrane, but rather the sleeves simply press a piece of film out of this. The remaining edge is frayed and thus shreds of paper or film project into the passage which was supposed to be cleared. These shreds often project downwards into the container and on pouring or shaking out possibly block the path of the air flowing from outside into the container, or the even project into the path of the outflowing jet of liquid or the poured product. With larger packagings having stronger film-reinforced paper or cardboard the opening procedure is carried out even less reliably and cleanly. The sleeve moving slowly downwards and rotating at the same time, with its complete lower edge quasi simultaneously contacts the film-reinforced paper web which is to be cut open and as a whole presses it downwards and rotates on it until a hole is scraped open or broken through rather than cleanly cut open. One problem lies in the fact that the film to be cut open gives way slightly to the pressure of the sleeve acting to a certain extent as a drill bit, and thus the sleeve no longer acts on a paper film which is plane but on one which is curved downwards. Furthermore, the previous solutions demand a significant force on the part of the user as a result of the design of the sleeves, which are aptly also called penetrators, because indeed they penetrate a piece of paper film rather than cleanly cutting a circular disk out of it. That is to say, a large torque must be exerted since the teeth or tearers on the lower penetrator edge or sleeve edge firstly merely scratch the film and then they must overcome a large resistance to rotation. In the uppermost layer of the paper thickness they act similarly to tear-open teeth, specifically in a scraping, pressing and tearing manner, rather than acting as actual cutting blades. In order to facilitate the breaking out or tearing out for conventional self-opener closures of this type, the film material or the composite material is pre-weakened at the desired tear locations by means of lasers or punching tools. However, this pre-weakening entails much technological effort. Expensive installations are required and the handling for the machining of the penetration locations on the films is time-consuming. In spite of these elaborate weakening measures, the conventional self-opener closures do not cut cleanly, but tear the paper or plastic film rather than cleanly cutting it open, which explains the large resistance to rotation. On account of these large rotation resistances, even breakages of the means which should effect the transmission of the torque from the threaded cap to the penetrator sleeve occur, or the catching cams provided to engage into grooves on the penetrator sleeve can jump out of these grooves. If this happens, the self-opener closure is no longer capable of functioning.